Control switch for an electric dry razor



Jan. 13, 1970 K. BAUMANN CONTROL SWITCH FOR AN ELECTRIC'DRY RAZOR FiledAug. 15 1967 2 Sheets-Sheet 1 INVENTOR: M

Jan. 13, 1970 K. BAUMANN 3,489,874

CONTROL SWITCH FOR AN ELECTRIC DRY RAZOR Filed Aug. 15, 1967 2Sheets-Sheet 2 5 FIG. 3

INVENTOR:

United States Patent O 3,489,874 CONTROL SWITCH FOR AN ELECTRIC DRYRAZOR Kurt Baumann, Solingen-Merscheid, Germany, assignor to RobertKrups, Solingen-Wald, Germany, a firm Filed Aug. 15, 1967, Ser. No.660,764 Int. Cl. HOlh 3/32 US. Cl. 200154 11 Claims ABSTRACT OF THEDISCLOSURE A control switch for an electric dry razor having anoperating knob with a lug secured thereto the lug cooperating with awedge-shaped projection on a control member to urge the member to one orother of spaced positions to open or close a pair of electrical contactscontrolling a motor for the razor. The member may slide in the casing orbe pivoted and rockable.

BACKGROUND OF THE INVENTION The invention concerns a control switch foran electric dry razor having an on-ofi switch separate from the cableconnection. In known devices of this type long connecting leads havebeen provided between the on-off switch and the cable connection.

The invention is intended to mitigate this disadvantage and further toimprove devices of the type mentioned above.

SUMMARY OF THE INVENTION The wedge-shaped projection of the spring orcontrol member advantageously lies with a wedge face against the lug onthe control or operating knob so that a component of the reaction forceacting on the spring member is active in the direction of movement ofsaid one contact. If the control knob is moved with its lug over thepeak of the projection of wedge shape there occurs a reversal of thereaction component acting in the direction of movement of said onecontact and the spring member jumps with the shifter bar into itsextreme position, in the opposite direction to the direction of movementof the control knob. In this way a snap action is achieved for theswitch by using simple mechanically robust structural members.

The arrangement makes do with a plate on which the electricallyconductive connections for the on-off switch and a voltage selectorswitch are combined structurally. The structural combination is achievedby securing or impressing the conductive connections together with thecontacts of the on-oif switch, tthe voltage selector switch and thecable connection onto tthe plate. In a preferred embodiment the voltageselector switch is disposed centrally of the plate and the plate isprovided at one end with connections to said pair of contacts for theon-oif switch and at the other end with the contacts, in particularcontact pins, for the connection cable to an electrical power supply.

The spring member is with advantage fork-shaped. It is also possible toprovide the lug on the control knob with one or more rollers in order toreduce the friction between the spring member and the lug on. thecontrol knob. The spring member may be adapted to slide or formed as apivoted rocker. A slide must be appropriately guided in the casing toprevent it moving in undesired directions.

A rocker must be appropriately mounted for pivotal movement andco-operates with said one contact of the pair of which is adapted toslide. The pivot is with advantage mounted at one arm of the member. Theother arm of the spring member formed as a rocker co-operates 'ice withthe lug on the control knob through its wedge shaped projection. Linearmovement of the control knob over the peak of the wedge-shapedprojection of the spring member causes a sudden rotary movement of thespring member about its pivot with the movable contact until a limit isreached, resulting in a rapid opening or closing of said pair of switchcontacts.

DESCRIPTION OF DRAWINGS Further details of the invention are illustratedby means of the drawings; two embodiments of the invention are shown inthe drawings in which:

FIG. 1 is a perspective view of a dry razor having a control switch, inlongitudinal view,

FIG. 2 shows a dry razor with the top open,

FIG. 3 is an elevation of the razor with half the casing removed,

FIG. 4 is a sectional side view,

FIG. 5 is an underneath plan view of a switch plate,

FIG. 6 is a longitudinal cross-section of a further embodiment showingthe switch in the off position,

FIG. 7 is a cross-section taken along the line VII indicated in FIG. 6,and

FIG. 8 is a view corresponding to FIG. 6 with the switch in the onposition.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings like referencesdenote like parts and only the parts of a dry razor 4 which arenecessary for comprehension of the invention are shown. The dry razor 4has as a handle, an elongated casing 5 which has on one wall 6 a controlknob 7 for an on-off switch 8 and has on the underside of the casing 5 avoltage selector switch 9 and recessed connection pins 10. The casing 5is divided into two shell halves 11 which are secured together by meansof a casing head 12 and in the lower region by means of screws 13.

The casing head 12 is sealed by a plate 14 and is set on both shellhalves 11 together with a cutter head 15. The casing 5 encloses anelectrical drive with an oscillating armature motor, the swing arm 16 ofwhich is visible and projects into the casing head 12 through an openingin the plate 14. On the casing head 12 there is mounted a carrierbracket 17 being hinged to open in a lateral direction.

The control knob or operating member 7 is provided With an inwardlydirected lug 19, and is adapted for displacement in a slot 21 providedbetween the two shell halves 11, as may be seen from FIG. 3. The lug 19carries a retaining plate 20 at the inside of the casing 5 andco-operates with a U-shaped spring member or control member 25 via atleast one projection 23. In FIGS. 3 and 4 the U-shaped member 25 is inthe form of a slide, is guided in the casing 5 in the longitudinaldirection and is manufactured in one piece with two parallel arms 26, 27and a base 28 from a body of synthetic material. The base 28 has a lug29, projecting beneath a frame 30 for the oscillating armature motor andco-operating with a stop 35 to limit downward movement of the member 25,and is supported by a lug 31, slidable against the inner wall of thecasing 5. The arms 26, 27 each bear one of the projections 23 defined byinclined surfaces.

The member 25 co-operates at its bottom end with a switch plate 32,arranged in the lower region of the casing 5, and bearing a contact arm33 shown in the off position which in an on position bridges across twocontacts 34a and 34b on the switch plate 32. When the member 7 isactuated, the lug 19 is moved over the peaks of the projections 23,resulting in a reversal of the reaction component acting on the contactarm 33 caused by spring action'of the member 25 and the inclinedsurfaces of the projections 23. The member 25 thus moves rapidly withthe contact arm 33 into its opposite extreme position as soon as the lug19 has moved past the peaks of the projections 23. A movement of theactuating knob 7, in the direction indicated by the arrow in FIG. 3,causes movement of the switch member 33 in the opposite direction andthus closes the switch contacts 34a and 34b.

The contacts 34a and 34b are secured at one end on the switch plate 32,and are conductively connected at the opposite end of the switch plate32 to two socket j members 34' (FIG. for the connections pins 10, by

printed circuit members 36. Pairs of contact members 37 are mounted onplate 32 and the voltage selector switch 9, which is of a knownconstruction, and is mounted for rotation with its axis in a hole 38 isthe switch plate 32.

In FIGS. 6 to 8 a fork-shaped control member 125 of the on-off switch 8having arms 126, 127 and a stem operating portion 139, is mounted in acasing 105 for pivotal movement about the arm 127. The other arm 126co-operates with a roller 122 carried by a lug 119 secured to theoperating knob 7, via a projection 123 with inclined planes 124 providedon the arm 126. The stem 139 co-operates with a movable contact member140 formed as a slide, the contact member 140 is formed in one piecewith a U-shaped spring 141 and co-operates with a stationary contact142. The U-shaped spring 141 and the stationary contact 142 are securedby bent over portions 145 in slots 143 in a base plate 144. Theforkshaped member 125 acts as a rocker and is mounted on a pin 146 whichis secured in the casing 105 parallel to and at a spacing from theroller 122. Flanges 147 are provided at opposite ends of the pin 146,one of which flanges 1-47 serves for fastening the pin 146 to the casing5.

Movement of the operating knob 7 upwardly as shown causes the roller 122to ride over the projection 123 and the fork-shaped member 125 to pivotin an anti-clockwise direction from the position shown in FIG. 6 to theposition shown in FIG. 8. Such movement effects contact between themovable contact 140 and the stationary contact 142 to energise themotor.

As already mentioned, the figures only show embodiments of the inventionby way of example and the invention is not intended to be limited ofthese embodiments; on the contrary other embodiments and uses are alsopossible. Particularly the arms 126 and 127 may be in the form of leafsprings and be set into the base 128. The inclined faces of theprojection 123 may also be steeper or flatter according to theparticular closing strength desired for the switch contacts.

Iclaim:

1. A switch, comprising, in combination, support means; a pair ofcontact means mounted on said support means for opening and closing acircuit connected to said contact means; an operating member mounted onsaid support means movable along a predetermined path between two endpositions; and a control member mounted on said support means movablebetween a first and a second position, said control member having anoperating portion cooperating with one of said contact means for openingsaid circuit in one of the positions of the control member and forclosing said circuit in the other position thereof, said control memberincluding a pair of arms connected at one end to each other and at leastone of said arms being resilient and carrying in the region of the freeend thereof a wedge-shaped projection projecting toward the other arm,said wedge-shaped projection being located in the path of said operatingmember and resiliently engaging with one face thereof said operatingmember when the latter is in one of its end positions so that saidcontrol member is held in one of its positions and the apex of saidprojection snaps over said operating member during movement of thelatter from said one to the other of its end positions so that the otherface of said wedge-shaped projection resiliently engages said operatingmember to move thereby said control member to the other of saidpositions thereof.

2. A switch as defined in claim 1, wherein both arms of said controlmember are resilient and each carrying in the region of the free endthereof one of said wedgeshaped projections projecting toward eachother, said operating portion being in the region of the connected endsof said arms, said operating member being in one of said end positionsthereof located between said arms.

3. A switch as defined in claim 1, wherein said control member is madeof insulating material.

4. A switch as defined in claim 2, wherein said control member ismounted on said support means moveable in direction of said path of saidoperating member, and including stop means on said support means forlimiting movement of said control member in one direction.

5. A switch as defined in claim 4, wherein said pair of contact meanscomprises a fixed contact and a resilient contact resiliently engagingsaid operating portion of said control member to urge the latter inengagement with said stop means.

6. A switch as defined in claim 1, wherein said control member ispivotably mounted on said support means.

7. A switch as defined in claim 6, said projection being provided on thefree end of one of said arms and the other of said arms being at thefree end thereof connected to said support means pivotable about a fixedpivot axis, said operating portion of said control member projectingfrom the connected ends of said arms in engagement with one of saidcontact means, and said operating member being in one of the endpositions thereof located between said arms.

8. A switch as defined in claim 7, wherein said one contact means isresilient and biases said control member means and said control memberare located, and said operating member comprises an operating knoboutside 9. A switch as defined in claim 1, wherein said support meanscomprises a casing in which said contact for pivotal movement in onedirection about said pivot axis. of said casing and a lug extendingthrough a slot in said casing into the interior of the latter andcooperating with said at least one projection on said control member.

10. A switch as defined in claim 9, wherein said lug comprises a rollercooperating with said at least one projection.

11. A switch as defined in claim 9 wherein said sup port means comprisesfurther an insulating plate extending transverse to said casing, saidpair of contact means being mounted on said insulating plate and saidcircuit being at least in part formed by a printed circuit on saidinsulating plate, and including connecting means on said casing forconnecting said circuit to a supply of electrical energy.

References Cited UNITED STATES PATENTS 3,009,999 11/1961 Johnson 200157XR 3,156,804 11/1964 Springer et al. 200157 3,200,212 8/1965 Barcus eta1.

3,243,528 3/1966 Brady 200 153.l1 XR 3,372,247 3/1968 Lock et al.200153.1l 3,204,053 8/1965 Bilek 200153.11 X

ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant ExaminerU.S. Cl. X.R. 20077, 153, 157

